Anole Annals

Anolis planiceps from Trinidad. Image from The Herpetology of Trinidad & Tobago.

I am a West Indian amateur herpetologist and member of the AA family for the past 5-6 years.

I have travelled and photo-documented anole species along the Eastern Caribbean archipelago from Curaçao in the south to Anguilla in the north. In so doing, the colour patterns of each endemic species have instilled a special thrill to my senses.

Anolis aeneus in Trinidad. Photo from The Herpetology of Trinidad & Tobago

However, it is in my home island of Trinidad where a unique spectacle lays in wait of thoughtful analysis. In the urban areas of Port-of-Spain (especially in the suburb of Woodbrook), Anolis aeneus is common on fruit trees, running along house walls and even venturing through windows into home interiors, displaying their speckled glory.

Yet a mere 60 miles to the northeast in the rural village of Fishing Pond (my home village), the anole species A. planiceps rules unchallenged, without the presence of A. aeneus. However, the sighting of A. planiceps is as rare as hen’s teeth (to use a local saying), running along the ground to mount the nearest tree trunk when seen occasionally.

Instead, along my house walls (in that rural area), three lizard species predominate: Ameiva atrigularis and Cnemidophorus lemniscatus, both teiid ground dwellers, as well as Gonatodes vittatus, a gekkonid tree/wall climber. Occasionally, three other species can be seen: Polychrus marmoratus and Tropidurus plica,  in the same family as anoles, as well as Mabuya bistrata, a skink in the Scincidae family. The last three are known to be tree/wall climbers. None of these six species are likely to be seen in the urban areas previously mentioned, where household cats and early morning birds seem not to deter the presence of A. aeneus.

My question, therefore: does interspecific competition for food and habitat (and maybe predation) from the other six rural lizard species keep A. planiceps from having larger populations? No other Eastern Caribbean island seems to harbour such an anomaly, except maybe St.Vincent with its elusive A. griseus which is in an environment with few other lizard species.

I await the views of the more learned and experienced members of the AA family.

In closing I’m aware that A. aeneus‘  home base extends to Grenada and the Grenadine Islands, while A. planiceps‘  base extends to Venezuela and  Guyana.

See the volume: “A Field Guide to the Amphibian & Reptiles of Trinidad & Tobago” by John Murphy et al.

Cheers,
Reynold C. Boyce

Anolis porcatus was recently introduced into Brazil. Now a paper in Herpetology Notes reports predation on that species by an introduced spider.

Anolis gundlachi. Photo by Alejandro Sanchez.

A recent study published in Biotropica by Beard et al. (2020) examines the impact of removing anoles (Anolis gundlachi, specifically) and perhaps the Caribbean’s most iconic frog, the coquí (Eleutherodactylus coqui), on arthropod densities.

Lizard and frog removal increases spider abundance, but does not cascade to increase herbivory.

Beard, K. H., Durham, S. L., Willig, M. R., & Zimmerman, J. K.

Abstract:

Insectivorous vertebrates, especially on islands, can exert top-down control on herbivorous prey, which can transfer through a food chain to reduce herbivory. However, in many systems insectivorous vertebrates feed on more than one trophic level, especially consuming arthropod predators, and this intraguild predation can diminish trophic cascades. Our goal was to determine, using an exclosure experiment, the relative importance of anole lizards and coqui frogs in controlling spider and arthropod abundances as well as herbivory rates in the understory of the Luquillo Experimental Forest, Puerto Rico. We found that exclosures removing both anoles and coquis doubled spider abundance compared to exclosures with anoles and coquis at natural densities. The effect of coquis on spiders was greater and occurred more quickly than that of anoles, potentially because of the higher natural densities of coquis and removal of both vertebrates produced no interactive effects. We found support for the idea that anoles, but not coquis, reduce foliar arthropod abundances on one of the two studied plant species. However, there was also evidence that anole removal decreased herbivory, the opposite of what we would expect if there was a trophic cascade. Potential explanations include that anoles reduced predatory arthropods on foliage more than they reduced herbivorous arthropods. Results highlight that the food web in tabonuco forest is not simple and that there are complex and dynamic relationships among vertebrate insectivores, predatory arthropods, and herbivorous arthropods that do not consistently result in a trophic cascade.

Anolis bartschi. Photo by Shea Lambert

Anolis bartschi is one of the many spectacular anoles of Cuba. Hailing from a restricted area in western Cuba, little is known about this species (though see a previous Anole Annals dispatch).

A new paper just out in Phyllomedusa provides new diet data. Here’s some details:

Trophic ecology and morphology of Anolis bartschi  (Squamata: Dactyloidae) in Viñales National Park, Cuba

L. Yusnaviel García-Padrón, Geydis León Amador, Mariela Mezquía Delgado, and Yusvel Martínez Serrano

Abstract

Trophic ecology and morphology of Anolis bartschi (Squamata: Dactyloidae) in Parque Nacional Viñales, Cuba. Little is known about the trophic ecology of most anoles of Cuba. Morphology is directly related to ecological functions in lizards, such as feeding strategies, interspecific competition or energetic demands linked to reproduction. Anolis bartschi is a regionally endemic species, restricted to karstic hills of western Cuba. Here, we offer new insights into the trophic ecology of this species, and its relation to head morphology. We captured 131 adults; males were larger than females in size and head width. Most of them had prey in their stomachs. Males consumed more prey than females, but the latter consumed larger prey. Prey overlap within sexes was detected in the dry season, but trophic segregation occurred in the rainy season. Hymenoptera was the most frequently consumed prey in both sexes. In addition, females ate Blattodea and Coleoptera, and males consumed more Diptera. We suggest that this lizard prefers sedentary rather than mobile prey. According to our dataset and field observations, A. bartschi is a bimodal forager lizard, but research on temporal (daily and annual) variation in diet is recommended for a proper forage classification of this lizard.

Here is a short film I made concerning green and brown anoles in Florida and their behaviors and physical differences. Follow me on Instagram @dailyanole!